“Since joining Aimmune in mid-June, I have been enormously pleased to see a strong team in place and solid progress towards submitting a Biologics License Application for AR101 in peanut allergy by the end of this year,” said Jayson Dallas, M.D., President and CEO of Aimmune. “Our intention in developing AR101 is to provide a reliable, robust level of protection with the convenience of daily oral dosing so that people living with peanut allergy can have peace of mind and more freedom in their daily lives. We are laser focused on continuing to move AR101 towards potential approval and preparing for a potential U.S. commercial launch in 2019. With an estimated 1.6 million peanut-allergic children and adolescents in the United States alone, we believe the market opportunity is very large. We are motivated by the widespread enthusiasm we hear from allergists and patients who are eager for an approved biologic oral immunotherapy. It is truly exciting to lead Aimmune into its next phase of becoming a fully integrated commercial organization with a pipeline of opportunities in other significant food allergies. I look forward to sharing our progress in the months ahead.”

Second Quarter Highlights

AR101: Pivotal-stage biologic for the treatment of peanut allergy

Announced new clinical data at the Congress of the European Academy of Allergy, Asthma, and Immunology (EAACI) showing efficacy across the intent-to-treat population of peanut-allergic patients enrolled in the Phase 3 PALISADE trial of AR101.

Announced results from an Aimmune-supported survey of more than 100 U.S. allergists showing that more than 80 percent preferred the term “tolerated dose” as the most clinically meaningful relevant term to communicate desensitization levels to oral immunotherapy patients.

Announced results from a new pan-European study showing significant psychosocial burden associated with peanut allergy, with a daily impact on more than 80 percent of people with peanut allergy and parents or caregivers of peanut-allergic minors.

Corporate

Appointed Dr. Jayson Dallas, an experienced leader with an extensive record of global strategic and commercial operational accomplishments and successful product launches, as President and Chief Executive Officer.

Second Quarter Financial Results

For the quarter and six months ended June 30, 2018, net loss was $52.6 million and $102.1 million, respectively, compared to net loss of $32.5 million and $58.4 million for the comparable periods in 2017.

On a per share basis, net loss for the quarter and six months ended June 30, 2018, was $0.91 and $1.83, respectively, compared to net loss per share of $0.65 and $1.16 for the comparable periods in 2017. The weighted average shares outstanding for the quarter and six months ended June 30, 2018 was 57.9 million and 55.8 million, respectively, compared to 50.2 million shares for the comparable periods in 2017. In the first quarter of 2018, the Company completed an underwritten public offering with net proceeds of $190.4 million through the sale and issuance of an aggregate of 6,325,000 shares of common stock.

Research and development expenses for the quarter and six months ended June 30, 2018, were $35.3 million and $68.7 million, respectively, compared to $22.2 million and $39.6 million for the comparable periods in 2017. The increase was primarily due to higher costs from the progression of certain AR101 clinical trials, including RAMSES, ARC008, ARC009, ARTEMIS and ARC011, and higher contract manufacturing costs to support clinical development and regulatory activities.

General and administrative expenses for the quarter and six months ended June 30, 2018, were $18.6 million and $35.2 million, respectively, compared to $10.8 million and $19.7 million for the comparable periods in 2017. The increase was primarily due to additional employee-related costs and external professional services as Aimmune continues to build its infrastructure to support the development and potential commercialization of AR101. Stock-based compensation expense also increased primarily due to the expansion and extension of our long-term commercial supply agreement with Golden Peanut Company and modification of certain executives’ stock options resulting from their planned separation.

Cash, cash equivalents, and investments totaled $295.9 million at June 30, 2018, compared to $182.4 million at December 31, 2017. The increase primarily reflects net cash proceeds of $190.4 million received as of June 30, 2018, from the sale of common stock, partially off-set by cash used in operating activities of $76.3 million and cash used for purchase of plant and equipment of $6.2 million.

Anticipated Upcoming Milestones

Timing

Anticipated Milestone

2H 18

Safety and tolerability data available from real-world utilization study of AR101 (RAMSES)

2H 18

Initiate a study of AR101 in infants and toddlers 1 – 4 years old (ARC005)

Submit Investigational New Drug Application for AR301 in walnut allergy

2H 19

Initiate Phase 2 clinical trial of AR301 in walnut allergy

2H 19

Potential approval and commercial launch of AR101 in the U.S.

About Aimmune Therapeutics

Aimmune Therapeutics, Inc., is a biopharmaceutical company developing treatments for life-threatening food allergies. The company’s Characterized Oral Desensitization ImmunoTherapy (CODIT™) approach is intended to provide meaningful levels of protection against allergic reactions resulting from accidental exposure to food allergens by desensitizing patients with defined, precise amounts of key allergens. Aimmune’s first investigational biologic product using CODIT™, AR101 for the treatment of peanut allergy, has received the FDA’s Breakthrough Therapy Designation for the desensitization of peanut-allergic patients 4-17 years of age. Aimmune plans to submit regulatory filings for marketing approval of AR101 in the United States and Europe based on data from the pivotal Phase 3 PALISADE clinical trial of AR101, which in 4-17 year-old subjects met all its primary and secondary endpoints, and additional ongoing and completed AR101 clinical trials. For more information, please see www.aimmune.com.

Forward-Looking Statements

Statements contained in this press release regarding matters that are not historical facts are “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995. Because such statements are subject to risks and uncertainties, actual results may differ materially from those expressed or implied by such forward-looking statements. Such statements include, but are not limited to, statements regarding: Aimmune’s expectations regarding the potential benefits of AR101; Aimmune’s expectations on the potential size of the market opportunity in peanut allergy; Aimmune’s expectations for the RAMSES, ARTEMIS and ARC004 trials, including the expected timing of data readouts and data cuts for these trials; Aimmune’s expectations on regulatory submissions for marketing approval of AR101 in the United States and Europe, including the timing of these submissions; Aimmune’s expectations regarding the potential commercial launch of AR101, including the timing of a potential approval or AR101; Aimmune’s expectations regarding the timing of initiating additional clinical trials for AR101, including ARC005 and a trial exploring AR101 with adjunctive dupilumab; Aimmune’s expectations on the timing of submitting an IND and initiating phase 2 clinical trials for AR201 in egg allergy and AR301 in walnut allergy; and Aimmune’s expectations regarding potential applications of the CODIT™ approach to treating life-threatening food allergies. Risks and uncertainties that contribute to the uncertain nature of the forward-looking statements include: the expectation that Aimmune will need additional funds to finance its operations; Aimmune’s ability to initiate and/or complete clinical trials; the unpredictability of the regulatory process; the possibility that the results of early clinical trials may not be predictive of future results; the possibility that Aimmune’s clinical trials will not be successful; Aimmune’s dependence on the success of AR101; Aimmune’s reliance on third parties for the manufacture of its product candidates; possible regulatory developments in the United States and foreign countries; and Aimmune’s ability to attract and retain senior management personnel. These and other risks and uncertainties are described more fully in Aimmune's most recent filings with the Securities and Exchange Commission, including its Quarterly Report on Form 10-Q for the quarter ended June 30, 2018. All forward-looking statements contained in this press release speak only as of the date on which they were made. Aimmune undertakes no obligation to update such statements to reflect events that occur or circumstances that exist after the date on which they were made.

This press release concerns a product that is under clinical investigation and that has not yet been approved for marketing by the U.S. Food and Drug Administration (FDA) or the European Medicines Agency (EMA). It is currently limited to investigational use, and no representation is made as to its safety or effectiveness for the purposes for which it is being investigated.

AIMMUNE THERAPEUTICS, INC.

CONDENSED CONSOLIDATED BALANCE SHEETS

(In thousands)

June 30,

2018

(Unaudited)

December 31,2017 (1)

Assets

Cash and cash equivalents

$

142,157

$

73,487

Short-term investments

147,843

108,943

Prepaid expenses and other current assets

6,826

6,681

Total current assets

296,826

189,111

Long-term investments

5,901

—

Property and equipment, net

23,265

17,205

Prepaid expenses and other assets

664

618

Total assets

$

326,656

$

206,934

Liabilities and Stockholders’ Equity

Current liabilities

$

36,094

$

26,599

Other liabilities

2,724

2,530

Stockholders’ equity

287,838

177,805

Total liabilities and stockholders’ equity

$

326,656

$

206,934

(1) Derived from the audited financial statements, included in the Company's Annual Report on Form 10-K for the year ended December 31, 2017.